The invention relates to the electronic marking of medication cartridges or the like.
The invention relates specifically to: A method of providing an electronically readable item of information on a medication cartridge.
The invention furthermore relates to: A medication cartridge with an information-providing source containing an electronically readable item of information.
The invention furthermore relates to: A support for a medication cartridge provided with an electronically readable item of information.
The invention moreover relates to: A medication delivery device having means for processing and displaying information.
The invention moreover relates to: An information carrier with an electronically readable item of information for a medication cartridge.
The following account of the prior art relates to one of the areas of application of the present invention, cartridges containing medication for injection, infusion or inhalation by a user.
In applications of medication delivery devices for self-treatment of a disease, e.g. diabetes, cartridges containing medication for a certain number of doses are mounted in the delivery device and exchanged with a new one when empty or when another medication is to be used according to the particular situation. It is of paramount importance that the medication used is the intended one, that it is not too old, that it has the correct concentration etc. Therefore the marking of the cartridge containing the medication has to be given special attention. To aid the user in achieving a satisfactory level of security in the use of a medication delivery device, a marking of the cartridge in addition to a traditional alphanumeric inscription has been introduced. Apart from information on the contents of the cartridge, the item of information may hold technical data on the type of cartridge, outlet dimension or other information of relevance to the medication delivery process.
U.S. Pat. No. 5,954,700 discloses a cartridge for containing a fluid and for use with an electronic delivery device that includes a cartridge housing for holding the fluid, and an information providing source. The information-providing source may be a set of wires and contacts, or contact bands that provide the predetermined information to an electronic delivery device by producing a binary code.
The possible spill of drops of the medication from the medication cartridge may typically deteriorate the readability of the optically readable or electronically readable coded information on the cartridge due to chemical reactions. This calls for a method of marking that is robust and does not allow the introduction of errors in the interpretation of the coded information in case of minor deteriorations of the code in question.
The problem of the prior art is to provide a method of marking a cartridge, which method is simple and safe and easily readable by electronic means.
Thus, the object of the present invention is to provide an alternative method of generating an electronically readable item of information on a cartridge which method is simple and improves safety in reading.
This is achieved according to the invention in that said item of information is redundantly provided. In this way, a very simple method is provided that may be implemented in a multitude of ways, customized to each specific application.
In the present context, the term xe2x80x98cartridgexe2x80x99 is taken to mean a container for holding a liquid or powder or other matter of a size and weight that can be handled by hand. The cartridge may e.g. be a cartridge containing medication for use with a medication delivery system for self-treatment of a disease. The medication in the cartridge may e.g. be insulin for use with a pen-type injection system for treating diabetes.
In a preferred embodiment said item of information is provided at least once in a binary true and inverted form.
In the present context, the term xe2x80x98redundantly provided in a binary true and inverted formxe2x80x99 is taken to mean that the information is provided in a way that may be directly translated to a binary representation (e.g. 100110) and that the same item of information is provided in its true (e.g. 100110) and inverted (011001) form, yielding a redundancy that may be used to check the validity of the electronically read code. I.e. if e.g. one or more of the (xe2x80x98should bexe2x80x99) inverted bits equals the corresponding bits of the true representation, an error is present. This check gives a higher degree of safety in interpreting the item of information in question, which e.g. is important when the container is used for medication in connection with a person""s self-treatment of a disease.
Apart from the above mentioned redundancy, each item of information (in its binary true or inverted forms) may be subject to standard error detecting measures, such as reserved bits for a parity check, a CRC (Cyclic Redundancy Check) or the like, and/or error correcting measures.
When said item of information is provided in any one of its binary forms by forming electrically insulating and electrically conducting areas corresponding to the relevant state of each bit of information in predefined positions on the surface of the cartridge, it is ensured that a very simple, flexible and inexpensive method is provided.
When said medication cartridge has an axis of rotational symmetry, it is ensured that a reading procedure that is independent of the rotational orientation of the cartridge is possible. This makes the positioning procedure of the cartridge in the medication delivery device convenient for the user in that he or she does not have to think about its correct orientation in the circumferential direction, defined as a circumference on the surface of the cartridge in a direction perpendicular to the axis of symmetry (also termed the xe2x80x98radial directionxe2x80x99in the following).
When said electrically insulating or electrically conducting areas fully or partially circumfere said axis of symmetry, thus defining two or more information carrying areas, each containing said item of information in its binary true or inverted form, on said cartridge, it is ensured that the reading of the information may be made independent of the radial orientation of the cartridge.
When said electrically insulating or electrically conducting areas are positioned in one or more longitudinal areas stretching in the direction of said axis of symmetry, each longitudinal area covering only a fraction of the circumference of said cartridge, thus defining two or more information carrying areas, each containing said item of information in its binary true or inverted form, on said cartridge, it is ensured that information carrying areas may be evenly distributed in the radial direction of the cartridge, and thereby making the reading of the information independent or nearly independent of the radial orientation of the cartridge.
When said item of information is provided in any one of its binary forms by applying electrically insulating areas to predefined positions on an electrically conducting foil, said foil being positioned on said cartridge, it is ensured that a very simple and convenient method for adding an electronically readable item of information to a cartridge is provided, which method is well suited for mass production.
When said item of information is read by applying a voltage to said electrically conducting foil, said voltage corresponding to the supply voltage of one of the logic levels of a digital processing circuit, and by connecting each predefined position on the foil electrically with inputs to a digital processing circuit, it is ensured that a very simple, and inexpensive method is provided that may take a variety of forms, customized to each specific application. It further has the advantage that no additional components or extra, customized wiring on the cartridge is necessary in order to define and electronically read a specific item of information.
When said inputs to the digital processing circuit are provided with pull-up or pull-down circuitry according to which of the supply voltages of the logic levels of said digital processing circuit is applied to said electrically conducting foil, it is ensured that a simple and easily producible scheme is provided.
When said inputs to the digital processing circuit may be selectably provided with either pull-up or pull-down circuitry according to which of the supply voltages of the logic levels of said digital processing circuit is correspondingly selectably applied to said electrically conducting foil, said selection being controlled by said digital processing unit, it is ensured that the probability of falsely reading the item of information in question is reduced.
When the redundant information from two or more information carrying areas on the cartridge is transferred to a contact area that is connected to a processing circuit by supporting means for the cartridge, the supporting means being at least partially constituted by two or more electrically connecting supports, each comprising a number of closely spaced mutually electrically insulated conductors embedded in an electrically insulating material that stretches from one of the supporting surfaces of the cartridge to a contact area for receiving and transferring the information to said processing circuit, when said cartridge is positioned in said support, it is ensured that a flexible method of simultaneously supporting the cartridge and transferring the information from the cartridge to a contact area for further processing is introduced.
When each of said two or more electrically connecting supports is constituted by alternating layers of electrically conducting material of maximum thickness Tcl and electrically insulating material of maximum thickness Til, respectively, it is ensured that a method well suited for transferring a high information density is disclosed. By controlling the dimensions of the layer thicknesses and the corresponding geometries of the contact area and the information carrying areas, the information density may be controlled, i.e. by shrinking the layer thicknesses the information density may be increased.
When said alternating layers are made of elastic materials, it may be ensured that the electrically connecting supports conform to the shape of the cartridge when the cartridge is positioned in the support with a certain minimum pressure. I.e. it makes the support even more flexible and relaxes the tolerances to its conformity with the cartridge and with the contact area (e.g. pads on a printed circuit board (PCB) for connecting to a processing circuit on the PCB).
A medication cartridge with an information-providing source containing an electronically readable item of information is moreover provided by the present invention. When said item of information is redundantly provided at least once by applying electrically insulating and electrically conducting areas corresponding to the relevant state of each bit of information in predefined positions on the surface of the cartridge, it is ensured that a cartridge containing an electronically readable item of information implemented in a simple way is provided, which cartridge is well suited for being part of a system that requires a high safety in information transfer, such as e.g. a medication delivery system for self-treatment of a disease.
When said item of information is formed on a self-adhesive carrier positioned on the surface of the cartridge, it is ensured that a simple and convenient means for providing an item of information to a cartridge is provided.
In a preferred embodiment said cartridge has an axis of rotational symmetry.
In a preferred embodiment information carrying areas containing said item of information in its true and inverted forms, respectively, are positioned side by side in the direction of said axis of symmetry of said cartridge.
In a preferred embodiment information carrying areas containing said item of information in its true and inverted forms, respectively, are positioned side by side in the direction of a circumference of said axis of symmetry of said cartridge.
When information carrying areas containing said item of information in its true and inverted forms, respectively, appear alternatingly a multitude of times in a direction of a circumference of said axis of symmetry of said cartridge, it is ensured that the same item of information is provided redundantly and repeatedly, which potentially facilitates the reading process. Furthermore, when a rotational symmetry is introduced, a reading procedure that is independent of the rotational orientation of the cartridge is possible.
When said item of information is provided in any of its binary forms by applying electrically insulating areas in predefined positions on the surface of an electrically conducting foil positioned on said cartridge in such a way that an electrically insulating area is applied at those predefined positions representing one predefined binary state, and an electrically conductive area is provided at those predefined positions representing the complementary binary state, it is ensured that a simple, flexible and economic configuration for electrically transferring an item of information from a cartridge to a processing means is provided.
When said item of electronically readable information is provided on the cartridge in an optically readable form, it is ensured that the item of information included on the cartridge for being electronically read may be read also directly by a user and/or by an optical scanner.
A support for a medication cartridge provided with an electronically readable item of information is furthermore provided. When said item of information being redundantly provided at least once by forming at least two information carrying areas containing electrically insulating and electrically conducting areas corresponding to the relevant state of each bit of information in predefined positions on the surface of said cartridge, and said support for the cartridge is at least partially constituted by two or more electrically connecting supports, each comprising a number of closely spaced mutually electrically insulated conductors embedded in an electrically insulating material that stretches from one of the supporting surfaces of the cartridge to a contact area for receiving and transferring the information to a processing circuit, when said cartridge is positioned in said support, it is ensured that the item of information on the cartridge may be transferred to an electronic circuit via an xe2x80x98adapterxe2x80x99 that may be adjusted to the particular embodiment of the cartridge and the physical device which it is part of. A support of this type is further disclosed in our co-pending application xe2x80x9cA support for a cartridge for transferring an electronically readable item of information from the cartridge to an electronic circuitxe2x80x9d.
When each of said two or more electrically connecting supports is constituted by alternating layers of electrically conducting material of maximum thickness Tcl and electrically insulating material of maximum thickness Til, respectively, it is ensured that a simple and flexible solution is provided. By controlling the thicknesses of the two layer types, the maximum density of information may be controlled.
When said cartridge has an axis of rotational symmetry, and said contact area consists of groups of identical and regularly spaced electrically conducting pads of width Wcp in the direction of adjacent pads, adjacent pads being separated by an electrically insulating area of width Diacp, and the following relations between said distances are fulfilled:
Diacp greater than 2*Tcl,
and
Wcp greater than Til+Tcl,
it is ensured that the electrical states of adjacent (possibly abutted) predefined positions are not transferred to the same pad (Diacp greater than 2*Tcl), and that at least one conducting layer contacts any given pad (Wcp greater than Til+Tcl).
When said cartridge has an axis of rotational symmetry, and said cartridge is provided with a multitude of rectangular, essentially parallel, identically sized information carrying areas of height Hica in the direction of a circumference of said axis of symmetry, said information carrying areas being spaced with equal mutual distance Dica along the periphery of the cartridge in the direction of a circumference of said axis of symmetry, and said supporting means comprise two rectangular, essentially parallel, identical electrically connecting supports of height Hctm in the direction perpendicular to the axis of symmetry of the cartridge, separated by an electrically insulating volume of width Dctm between the two electrically connecting supports, and the following relations between said distances are fulfilled:
xe2x80x83Hica less than Dctm less than 2*Hica+Dica,
and
Hctm less than Dica less than 2*Hctm+Dctm,
it is ensured that the cartridge cannot be positioned in such a way that a given information carrying area has contact to two electrically connecting supports at the same time (Hica less than Dctm). It is further ensured that the cartridge cannot be positioned in such a way that a given electrically connecting support has contact to two information carrying areas at the same time (Hctm less than Dica). It is further ensured that the cartridge cannot be positioned in such a way that the electrically connecting supports fall entirely between two information carrying areas, in which case they would not have contact to any of the information carrying areas of the cartridge (Dica less than 2*Hctm+Dctm). It is further ensured that the cartridge cannot be positioned in such a way that two adjacent information carrying areas fall entirely between the electrically connecting supports, in which case the latter might not have contact to any of the information carrying areas of the cartridge (Dctm less than 2*Hica+Dica).
When said information carrying areas of height Hica each consist of electrically conducting and electrically insulating rectangular patches provided at said predefined positions on said cartridge according to a binary representation of said item of information, said patches having a width Wpda abut each other, and the sum of the maximum thicknesses Tcl and Til of said alternating layers of electrically conducting and electrically insulating materials, respectively, constituting said electrically connecting supports, is less than the width Wpda of said patches, thus fulfilling the following relation between said distances:
Wpda greater than Til+Tcl,
it is ensured that each patch has contact to at least one of the conducting layers of an electrically connecting support when the cartridge is properly placed in the support.
In a preferred embodiment said alternating layers of an electrically conducting material and an electrically insulating material comprising said electrically connecting supports are made of elastic materials.
When it is made of elastic materials, it may be ensured that the support conforms to the shape of the cartridge when the cartridge is positioned in the support with a certain minimum pressure. I.e. it makes the support even more flexible and relaxes the tolerances to its conformity with the cartridge and with the contact area (e.g. pads on a PCB for connecting to a processing circuit on the PCB).
A medication delivery device having means for processing and displaying information is moreover provided by the present invention. When it is adapted for receiving a cartridge according to any one of claims 14-21, and it comprises a support according to any one of claims 22-28 for electronically reading an item of information on said cartridge, and said support transfers said item of information from said cartridge to a contact area connected with said processing means, a safe and automatic reading of an item of information on the cartridge containing the medication to be injected, infused or inhaled by a user is provided. The item of information on the cartridge may appropriately include data on the physical contents of the cartridge, the volume/amount of medication in the cartridge, the last day of recommended use of the contents, dosage information, technical data on the type of cartridge, needle, piston (if relevant), etc. The processing means may be adapted to check whether the electronically read item of information matches the expected one and to process its contents. The processing means may further be adapted to check whether the cartridge is properly inserted in the medication delivery device or whether the cartridge is a correct one by suggesting the user to check this if the electronically read item of information does not match the expected one or if no information is read at all.
An information carrier with an electronically readable item of information for a medication cartridge is moreover provided by the present invention. When said carrier is a self-adhesive electrically conducting foil adapted for being positioned on said medication cartridge, and said item of information is redundantly provided at least once by applying electrically insulating areas to predefined positions on said foil, it is ensured that a convenient and flexible means for adding an electrically readable item of information to a cartridge is provided, said means being well suited for industrial handling, optionally containing the electrically readable items of information in an optically readable form as well, e.g. as a bar code and/or in a visually intelligible form.